HIV 'drug holidays' called into question

Shares

In people infected with HIV, helper T cells that express CD4 surface antigens gradually disappear from the blood as the immune system becomes weaker.

In a series of technically challenging experiments, Daniel Doeck of the US National Institutes of Health and colleagues show that HIV preferentially infects the HIV-specific CD4+ T cells. This evolutionary adaptation on the part of the virus enables it selectively to disable the specific immune response against it, thereby enabling persistent infection in an otherwise immunocompetent host.

The finding — published in the 2 May issue of Nature — raises questions over the practice of 'structured treatment interruptions', or 'drug holidays', a treatment regime that is currently the subject of a number of drug trials.

It raises the possibility that vaccine strategies aimed at increasing the frequency of HIV-specific CD4+ cells could serve only to increase the reservoir of infected cells.